We may not remember them, but we’ve all seen them. The average web users sees thousands of advertisements on a daily basis, from helpful search ads that deliver useful services to obnoxious display banners plastered across some of the world’s most popular websites.

While we may not like advertising, it exists for a reason: to keep the web (for the most part) free of charge for users, and give webmasters a source of income. The banner ads you see every day generate, in some cases, thousands of dollars for the website owners that are serving them up.

Of course, when money is being spent, advertisers want to get the most worthwhile bang for their buck. From misleading claims designed to improve sales to flashy and annoying graphics designed to get your eyes looking in their direction, there are no tricks that advertisers won’t try to get a few extra clicks for their dollars.

Let’s examine five of the most well-known banner ads of the last decade and look at what made them so effective, what made them so memorable, and what made them so annoying for web users.

The ‘Flat Belly’ Diet Ads

Arguably the most well known diet ad on the Internet, the ‘flat belly’ ads appeared in 2008 and haven’t disappeared since. Promoted on virtually high-traffic website you can think of, these ubiquitous diet ads are incredible hard to ignore.

Let’s look at the key factors that make these ads so effective. First, there’s the simple layout that immediately contrasts the color scheme of the website on which the ads are displayed. Then there’s the shrinking bikini animation – a massive eye-catcher that makes it tough to ignore the ad.

Finally, there’s the message – who doesn’t want to lose a few extra pounds? These ads tapped into people’s insecurities in a shameless manner, resulting in massive sales of otherwise questionable products.

Evony Online’s ‘Sex Sells’ Banner Ads

For those of you who aren’t familiar with Evony Online, it’s a free-to-play online web game that’s, well, not particularly modern. Dated graphics, poor design, clunky game mechanics – if you can name a problem, this game probably has it.

What it doesn’t have, however, is a bad advertising campaign. Evony’s banner ads are shamelessly sexy, designed from the ground up to capture the attention of web gamers using… well, tits and ass.

The game itself has minimal sexual content, which makes the advertising campaign something of a bait and switch strategy. Nonetheless, the ads were remarkably good for Evony’s bottom line and dominated the web from 2007 onwards.

The ‘Are You Smarter Than This B-List Celebrity?’ Ads

Online IQ tests have been around for almost a decade, and they’ve all operated using the same business model. A user clicks a giant, obnoxious banner ad, answers a few questions, and then types in their phone number to receive free IQ information.

It’s all a farce, of course: the IQ information isn’t even remotely accurate, and your phone is quickly signed up for hundreds of different services that you weren’t at all interested in receiving.

While the service may suck, the ads that are used to promote these IQ tests can only be described as ‘just short of genius.’ The celebrity ads, as pictured above, play on a desire amongst teenage girls to check if they’re smarter than their dream boy.

What makes the IQ ads so effective is the way they’re perfectly tailored to suit their target audience. Sports sites have athletes as the example, music sites have musical artists (think: Kanye West) that are known for their bizarre behavior. The entire ad effectively says: ‘we think you’re no smarter than Justin Bieber. Prove us wrong!’

Note: for some real irony, check the spelling and grammar mistakes in the lower bar of the ad. Looks like the designer isn’t smart enough for their own IQ test.

Those Annoying ‘Reduce Your Mortgage’ Ads

If you’ve ever visited a website that has anything to do with home repairs, mortgage refinancing, or anything even remotely related to property, you’ve no doubt seen the annoying ‘$990,000 mortgage for under $1 a month’ ads like the one pictured above.

Promising incredible discounts on mortgage payments, these ads include fake drop-down menus designed to make you think you’re customizing your mortgage options. Instead, you’re clicking through to a mortgage portal designed to get you to sign up for an incredibly expensive adjustable-rate mortgage for several decades.

These ads use several great psychological tricks. First, they play on everyone’s ‘good deal weakness.’ After all, who doesn’t want a lower mortgage payment? Second, they use ultra-simple graphics and bold text to grab your attention and convince you to click. In the world of online advertising, ugly often works better than beautiful.

The ‘You’re Our Millionth Visitor! Collect Your Prize!’ Ads

These annoying banners have, quite thankfully, disappeared from the Internet. One of the staples of early-2000s online advertising, these ‘flashing prize winner’ banner ads typically promised massive rewards for the millionth visitor to a website.

Of course, it was all nonsense: the banners were displayed on every unique website page view, and were designed solely to build an email database. While spammy and undoubtedly annoying, they demonstrate an important element of good advertising: make your users feel special and they’re much more likely to respond to you.